The Internet has emerged as a critical communication infrastructure, carrying traffic for a wide range of important applications. Internet services such as VoIP and SoIP services are becoming ubiquitous and more and more businesses and consumers are relying on their Internet connections for all voice and data communications. For example, businesses and consumers may connect their routers to the Internet for sending and receiving data packets. In turn, the routers utilize routing protocols to determine a path for sending the data. Internet protocol (IP) traffic follows rules established by routing protocols. Shortest path based protocols, such as Open Shortest Path First (OSPF), direct traffic based on arc weights that are assigned to each arc, e.g., by the network operator. The assigned weights are made known to each router in the network. Each router computes shortest paths and creates destination tables used for routing flow on the shortest paths. Traffic leaving a source router to a destination router is often split among all arcs leaving the source router on the shortest path graph towards the destination router. For example, a router continues to split traffic among all arcs on the shortest path graph even when a path may be congested. In addition, the installed capacity may not be enough to meet the demand during failure scenarios. However, if the capacity is increased well beyond the expected need, then the cost of the network becomes prohibitive and impractical.
Therefore there is a need for a method for providing composite link assignment in network design such that the capacity is enough to handle all the expected traffic while the total cost of the capacity is minimized.